Function asyncLruCache

src/modules/utils.ts:176–212

(
  size: number,
  ignoreIndices: number[] = []
)

}

export function asyncLruCache<ReturnType>(
  size: number,
  ignoreIndices: number[] = []
): (fn: AnyFunction<Promise<ReturnType>>) => AnyFunction<Promise<ReturnType>> {
  // The cache for storing function call results.
  const cache = new Map<string, Promise<ReturnType>>();

  return (
    fn: AnyFunction<Promise<ReturnType>>
  ): AnyFunction<Promise<ReturnType>> => {
    return async function (...args: unknown[]): Promise<ReturnType> {
      // Generate a cache key, ignoring specified arguments.
      const keyArgs = args.filter((_, index) => !ignoreIndices.includes(index));
      const key = JSON.stringify(keyArgs);

      // Check for a cache hit.
      if (cache.has(key)) {
        console.log('Cache hit:', key);
        return cache.get(key) as Promise<ReturnType>;
      }

      // Call the original function and cache the result.
      const result = fn(...args);
      cache.set(key, result);

      // Check the cache size and evict the least recently used item if necessary.
      if (cache.size > size) {
        const oldestKey = Array.from(cache.keys())[0];
        cache.delete(oldestKey);
        console.log('Evicted:', oldestKey);
      }

      // Return the result.
      return result;
    };
  };
}